Allow referencing code in imported file (right now for function calls, allow calling a function in another file)

1 files changed, 40 insertions, 6 deletions

diff --git a/include/bytecode/bytecode.h b/include/bytecode/bytecode.h
index b1b5dda..c495d7a 100644
--- a/include/bytecode/bytecode.h
+++ b/include/bytecode/bytecode.h
@@ -26,11 +26,15 @@
     6.2 Opcode(u8) + register(i8) + intermediate(u16)\
     6.3 Opcode(u8) + register(i8) + data(u16)\
     6.4 Opcode(u8) + flags(u8) + num_local_var_reg(u16)
-    7. 5 bytes: Opcode(u8) + index(u16) + num_args(u8) + register(i8)
+    7. 5 bytes: Opcode(u8) + index(u8) + index(u16) + num_args(u8)
     # Registers
     Registers have a range of 128. Local variables start from register 0 and increment while parameters start from -1
     and decrement. Registers have the scope of functions and reset after instructions reach a new function (AMAL_OP_FUNC_START).
+
+    If import index for call and calle is 0, then that means the function resides in the same file the function call
+    is being called from. Which means that import index 1 is actually import index 0 into the import list.
 */
+/* Important: The number of fields in this enum can't exceed 255 */
 typedef enum {
     AMAL_OP_NOP,         /* No operation (do nothing). This can be used for patching code */
     AMAL_OP_SETZ,        /* setz reg                             - Set register value to 0 */
@@ -46,16 +50,17 @@ typedef enum {
     AMAL_OP_PUSH,        /* push reg                             - Push register onto stack */
     AMAL_OP_PUSHI,       /* pushi int                            - Push intermediate onto stack */
     AMAL_OP_PUSHD,       /* pushd data                           - Push data onto stack */
-    AMAL_OP_CALL,        /* call fi, num_args, dst               - Call a function using function index (fi) and num_args arguments. The result is stored in register dst. fi is u16 and num_args is u8 */
+    AMAL_OP_PUSH_RET,    /* push_ret reg                         - Push register onto stack as a return value of the next function call */
+    AMAL_OP_CALL,        /* call ii, fi, num_args                - Call a function in imported file (ii, import index) using function index (fi) and num_args arguments. ii is u8, fi is u16 and num_args is u8 */
     AMAL_OP_CALLR,       /* callr reg, num_args                  - Call a function using a register. Used for function pointers. num_args is u8 */
-    AMAL_OP_CALLE,       /* calle efi, num_args, dst             - Call an extern function using extern function index (efi) and num_args arguments. The result is stored in register dst. efi is u16 and num_args is u8 */
+    AMAL_OP_CALLE,       /* calle ii, efi, num_args              - Call an extern function in imported file (ii, import index) using extern function index (efi) and num_args arguments. ii is u8, efi is u16 and num_args is u8 */
     AMAL_OP_CMP,         /* cmp dst, reg1, reg2                  - Set dst to 1 if reg1 equals reg2, otherwise set it to 0 */
     AMAL_OP_JZ,          /* jz reg, label                        - Jump to label in the current function if reg is zero. label is u16 */
     AMAL_OP_JMP,         /* jmp label                            - Unconditional jump to label in the current function. label is u16 */
     AMAL_OP_RET,         /* ret reg                              - Return from the function with reg result */
     AMAL_OP_FUNC_START,  /* func_start flags, num_local_var_reg  - Start of a function which has @num_local_var_reg local variable registers allocated and has the flag @flag. @flag is u8 and @num_local_var_reg is u16 */
     AMAL_OP_FUNC_END,    /* func_end                             - End of a function. Implementation should do a ret here */
-    AMAL_OP_LABEL,       /* label                                - Label. This is the target of a jump instruction. Jump instructions only jump to labels in the same function scope */
+    AMAL_OP_LABEL        /* label                                - Label. This is the target of a jump instruction. Jump instructions only jump to labels in the same function scope */
 } AmalOpcode;
 
 #define AMAL_BYTECODE_MAGIC_NUMBER (u32)0xdec05eba
@@ -63,6 +68,8 @@ typedef enum {
 #define AMAL_BYTECODE_MINOR_VERSION 0
 #define AMAL_BYTECODE_PATCH_VERSION 0
 
+#define AMAL_BYTECODE_SECTION_MAGIC_NUMBER (u32)0x004005e4 /* "section\0" in ascii */
+
 #define AMAL_BYTECODE_NUM_REGISTERS 256
 
 typedef enum {
@@ -72,13 +79,40 @@ typedef enum {
 
 typedef u8 AmalOpcodeType;
 
+/* TODO: Make sure this pragma pack works on all platforms */
+#pragma pack(push, 1)
+typedef struct {
+    u32 func_offset;
+    u8 num_params;
+    u32 params_num_pointers;
+    u32 params_fixed_size;
+
+    u8 num_return_types;
+    u32 return_types_num_pointers;
+    u32 return_types_fixed_size;
+} BytecodeHeaderFunction;
+#pragma pack(pop)
+
+/* TODO: Make sure this pragma pack works on all platforms */
+#pragma pack(push, 1)
 typedef struct {
+    u32 function_index;
+    #define parser_index function_index
+    u32 extern_function_index;
+} BytecodeHeaderImport;
+#pragma pack(pop)
+
+struct Bytecode {
     Buffer/*<headers + instruction data>*/ data;
-} Bytecode;
+    usize import_index;     /* Reference inside @data where imports start */
+    u32 funcs_index;        /* Reference inside @data where funcs start */
+    u32 extern_funcs_index; /* Reference inside @data where extern funcs start */
+    u32 offset;             /* Offset that this bytecode starts from in the final program (all bytecodes combined) */
+};
 
 typedef struct {
     jmp_buf env;
-    Bytecode bytecode;
+    Bytecode *bytecode;
     Parser *parser; /* borrowed */
 } BytecodeCompilerContext;